Abstract:
In my talk I will discuss some new
features of conformal anomaly and
entanglement entropy in the presence of
boundaries. The talk is based on recent
papers arXiv:1510.04566,
arXiv:1601.06418 and arXiv:1604.07571

Additional details of the upcoming Joint
Seminars in Theoretical High Energy Physics
can be found on the following link.

Abstract:
We propose a nonperturbative framework
to study general correlation functions of
single-trace operators in N = 4 SYM at
large N. The basic strategy is to
decompose them into fundamental
building blocks called the hexagon form
factors, which were introduced earlier to
study structure constants using
integrability. The decomposition is akin to
a triangulation of a Riemann surface, and
we thus call it hexagonalization. We
propose a set of rules to glue the
hexagons together based on symmetry,
which naturally incorporate the
dependence on the conformal and the R-
symmetry cross ratios. Our method is
conceptually different from the
conventional operator product expansion
and automatically takes into account
multi-trace operators exchanged in OPE
channels. To illustrate the idea in simple
set-ups, we compute four-point functions
of BPS operators of arbitrary lengths and
correlation functions of one Konishi
operator and three short BPS operators,
all at one loop. In all cases, the results are
in perfect agreement with the perturbative
data. We also suggest that our method
can be a useful tool to study conformal
integrals, and show it explicitly for the
case of ladder integrals.

Additional details of the upcoming Joint
Seminars in Theoretical High Energy Physics
can be found on the following link.

Lecturer: Dr. Kosuke Nomura
Affiliation: University of Tsukuba and
University of Zagreb

Abstract:
Like other finite quantum many-body
systems, atomic nucleus exhibits stunning
collective excitations that are associated
with geometrical shapes. The growing
interest in the study of nuclear shapes and
collective excitations, including those of
short-lived nuclei that are becoming
accessible in experiments at radioactive-ion-
beam facilities worldwide, necessitates a
timely systematic theoretical analysis. On the
other hand, the underlying nucleonic
dynamics is highly complex that a
quantitative, as well as reliable, description
of these phenomena presents a major
theoretical challenge.

This talk will focus on the recently developed
method that is constructed by bridging the
microscopic framework provided by the
nuclear density functional theory and
algebraic theory of interacting bosons. The
method has opened up many new
possibilities of analyzing complex nuclear
shapes and collective excitations in an
accurate, systematic and computationally
feasible manner. I will present the basic
notions of the method and highlight the
interesting applications, including the studies
of reflection asymmetric (or pear-shaped)
nuclei and nuclei with odd number of
nucleons, which are hot topics in nuclear
structure research in recent years.

Abstract:
Supernovae near the galactic center
evolve differently from regular galactic
supernovae. This is mainly due to the
environment into which the supernova
remnants propagate. Instead of a static,
uniform density medium, SNRs near the
galactic center propagate into a wind-
swept environment with a velocity away
from the galactic center, and a graded
density profile. This causes these SNRs
to be non - spherical, and to evolve
faster than their galactic counterparts.
We develop an analytic theory for the
evolution of explosions within a stellar
wind, and verify it using a hydrodynamic
code. We show that such explosions
can evolve in one of three possible
morphologies. Using these results we
discuss the association between the two
SNRs (SGR East and SGR A's bipolar
radio/X-ray Lobes) and the two neutron
stars (the cannonball and SGR J1745-
2900) near the galactic center. We show
that, given the morphologies of the SNR
and positions of the neutron stars, the
only possible association is between
SGR A's bipolar radio/X-ray Lobes and
SGR J1745-2900. The compact object
created in the explosion of SGR East
remains undetected, and the SNR of the
supernova that created the cannonball
has already disappeared.

Additional details of the upcoming Astrophysics'
seminars can be found on the following link.

Abstract:
Over the past 20 years, bright sources of
entangled photons have led to a renaissance in
quantum optical interferometry. Optical
interferometry has been used to test the
foundations of quantum mechanics and
implement some of the novel ideas associated
with quantum entanglement such as quantum
teleportation, quantum cryptography, quantum
lithography, quantum computing logic gates, and
quantum metrology. In this paper, we focus on
the new ways that have been developed to
exploit quantum optical entanglement in
quantum metrology to beat the shot-noise limit,
which can be used, e.g., in fiber optical
gyroscopes and in sensors for biological or
chemical targets. We also discuss how this
entanglement can be used to beat the Rayleigh
diffraction limit in imaging systems such as in
LIDAR and optical lithography and microscopes.

Abstract:
Transmission rates in broadband optical
waveguide systems are significantly
enhanced by launching many pulse
sequences through the same waveguide.
Since pulses from different sequences
propagate with different group velocities,
intersequence pulse collisions are very
frequent, and can lead to severe
transmission degradation. On the other
hand, the energy exchange in pulse
collisions can be beneficially used for
realizing fast control of the transmission.

In the current work we develop a general
approach for exploiting the energy
exchange in intersequence collisions for
transmission stabilization and switching,
using solitons as the optical pulses. Along
the way we also develop several methods
for solving one of the most challenging
problems in nonlinear waveguide optics -
the problem of stabilizing broadband
soliton transmission against resonant
emission of small-amplitude waves. Our
approach for transmission control is based
on showing that collision-induced
amplitude dynamics in N-sequence
waveguide systems can be described by N-
dimensional Lotka-Volterra (LV) models,
where the model's form depends on the
dissipative processes in the waveguide.
Stability and bifurcation analysis for the
equilibrium states of the LV models is used
to develop ways for achieving robust
transmission stabilization and switching
that work well for a variety of waveguides
including optical fibers and silicon
waveguides. Furthermore, we show that
supercritical Hopf bifurcations of the
equilibrium states of the LV models can be
used to induce large stable oscillations of
soliton amplitudes along ultra-long
propagation distances. The latter finding is
an important step towards realizing spatio-
temporal chaos with multiple sequences of
colliding solitons in nonlinear optical
waveguides.

Abstract:
Quantum thermodynamics deals with thermodynamic effects and thermodynamic constraints (e.g. the 2nd law) that emerge in out-of-equilibrium microscopic open quantum systems, and in microscopic heat machines. Presently, the technology developed for quantum computing is sufficient for exploring quantum thermodynamic experimentally (new experimental results will be shown). On top of the second law, thermodynamic resource theory predicts additional mathematical constraints on thermal transformation of microscopic systems. Unlike the second law, these constraints cannot be related to thermodynamic observables. Consequently, they are useful for some theoretical purposes, but not for making concrete predictions on realistic scenarios. In this talk I will present a new formalism that yields additional “seconds laws” that follow the logic and structure of the standard 2nd law. While the 2nd law deals with the first moment of the energy (average heat, average work), the observables in the new laws are higher moments of the energy. I will show several scenarios where these laws provide concrete answers to “blind spots” that are not addressed by the standard 2nd law. In other cases tighter bounds are obtained compared to the 2nd law. Potentially this formalism can significantly extend the thermodynamic framework, and put additional practical bounds on thermal transformations and microscopic heat machines. Finally I will discuss the connection to quantum coherence measures and list several research directions.